Women with obesity are frequently teased, judged, and shamed due to their weight. Internalizing weight-related stereotypes (e.g., that a person with obesity is inherently lazy and unmotivated) has been associated with physical activity (PA) avoidance. The purpose of this Solomon-square (half the participants in each condition completed a pretest) four-week online study was to determine if internalized weight bias (IWB) could be reduced in women with obesity using an implicit retraining task. This was a visual probe task that repeatedly paired non-stereotypical images of individuals with obesity being active with positive PA-related words (e.g., motivated, strong). This task was hypothesized to change automatic associations between PA and obesity (i.e., counter stereotypes related to weight and PA) through principles of evaluative conditioning. Participants in the experimental group (n=49) completed the implicit retraining once per week for three weeks. Their IWB scores were compared to those of participants in the control group (n=53) who read Canada's PA guidelines and were asked to create weekly PA goals. There was no effect of completing pretest measures on post-test IWB. Results of a repeated measures Analysis of Variance showed that women in the implicit retraining group had lower IWB than those in the comparison group at post-test (d=0.46) and at one-week follow-up (d=0.43), F (1, 102) = 5.583, p=.020. These findings suggest that portraying individuals with obesity in positive, non-stereotypical ways when promoting PA could reduce the effects of IWB and may play a role in promoting PA in women with obesity.